The present invention relates to a motorized spreader especially suited for spreading fertilizer, salt, and seed or the like and in particular to the drive train for the motorized spreader.
In conventional motorized fertilizer spreaders, the spreader includes a hopper for holding fertilizer and a hopper support frame. The support frame is mounted onto a set of wheels, which are mounted onto a drive axle and driven by a motor. The hopper may include one or more dispensing apertures through which the fertilizer is dispensed--in other words, the hopper operates on a gravity feed system.
In recent developments, augers have been positioned in the hopper to improve the control of the flow of the fertilizer from the hopper. In some applications, the auger is drivingly coupled to one of the wheels so that when the spreader is driven forward the auger rotates at a speed proportional to the wheel speed to dispense the fertilizer in the hopper onto the ground. When the spreader is being driven forward in a generally straight path, the fertilizer is dispensed relatively uniformly. However, when the spreader is turned, the speed of the auger will either increase or decrease depending on which wheel the auger is coupled. It will be understood for example that if the auger is coupled to the right forward wheel and the spreader is turned to the right, then the right wheel's speed will decrease and so too will the speed of the auger. This results in a reduced amount of fertilizer being dispensed from the hopper without a reduction in the area to be covered by the spreader and, consequently, results in a non-uniform distribution of the fertilizer onto the ground.
Other proposed fertilizer spreaders drivingly couple an impeller blade to the drive axle of a motorized spreader. For example, in U.S. Pat. No. 4,352,463 to Baker, a treatment spreader (10) includes a hopper (16) having a plurality of metering holes (17), (18), and (19). An impeller blade (40), which is carried on a vertical shaft (39), is supported below metering holes (17), (18), and (19). The vertical shaft (39) is meshed with a bevel gear (66), which is centrally located on the drive axle of the spreader so that rotation of the drive axle imparts rotating to the impeller blade (40). While the rotation of the impeller is controlled by the rotation of the drive axle, the flow of the fertilizer from the hopper through the metering holes is not correlated to the ground speed of the spreader. Instead, the flow of the fertilizer is controlled by the operator of the spreader through a lever (25) and a rod (30). While the uniformity of the fertilizer distribution is improved, the control of the fertilizer is within the discretion of the operator and, therefore, is subject to variation.